Improvement in steam safety-valves



ahmed tant' @time @fitte we massaaew "mf JOHN ASHCROFT, OF NEW YGR'K, N. Y.

Letters Patent No. 86,346, dated Februa/ry 2, 1869.

MPROVEMENT IN STEAM SAFETY-VALVES.

To all whom 'it 'may conce/ru:

Be it known that I, JOHN AsHcRoF'r, of the city, county, and State of New York, have invented a new and useful Improvement in Steam Safety-Valves for the boilers oi" locomotives and other steam-engines; and do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, making part of this specification, of which- Figure 1 represents a sectional elevation;

Figure 2, a horizontal section on line :v :c of iig. 1;

Figure 3, a horizontal section on line y y; and

Figure 4, a similar section on line z z of said figure.

This invention, relating to an improvement in steam safety-valves, consists in the constructions-and arrangement of the valve, its sustaining-dome and enclosingcase, in such manner that, as the valve (which is in direct communication with the steam in the boiler) is raised from its, seat, the steam will escape through the dome, without contact with the mechanism which operates said valve, or access to its enclosing-case.

The enclosing-case not only protects said mechanism irom dirt or derangement, but prevents access to the same by any other than the person in charge, being secured toY the dome by lock and key, and at the same time the engineer can operate the valve from without,4

whenever he thinks necessary to blowofi' steam, or prevent clogging of the valve, and by unlocking the case, the same may be removed for inspection of the valve-mech anism, when the steam is on, or at any. desired moment.

Having described the nature of my invention, I wil`l now describe its construction and operation, by reference to the drawings, in which- A indicates a portion of the shell of a steam-boiler, on which is bolted the.dome B, which sustains the enclosing-case U and valve D, as shown.

This dome receives the cap E, which is screwed into the dome at e, saidcap answering the purpose of a guide for'the valve-spindle d, as well asto confine the steam when the valve is raised, so that the steam shall escape around the guard F, which prevent-s access to the valve from without, and through the exit-opening G ofthe dome B, without access to the interior of the case C. l

The done B also receives the valve D, whose seat D is screwed into the domeatI I, and also the standard K, which, together with the fulcrum L, serrated leverM, and weight N, holds the valve D on its seat D'.

tention ofthe weight N, said weight having a tooth, n, which iits into one ofthe serrations of the lever, and a steadily in place.

P is a,crank-sliaft, passing through the case C, and carrying a cam, p, and crank, q, by means of which the engineer operates the valve for blowing oii' steam, 85o.

is the enclosing-case, made in two sections, c c', the same being held firmly together by the bolt R, which passes through both sections, having a head, s, nut, t, and a hole, u, .for reception of the lock w, thus holding the sections firmly together, the case C, which they comprise, enclosing the dome, valve, and valvemechanism, therebylpreventing access of the steam to the interior of the case, as well as preventing access to locking and removal of the case.

Having described, my invention,

What I claim, and desire to secure by Letters Patent, ls-

1. The arrangement of the dome B, screw-cap E, guard F, with the valves D D', when said parts are constructed as shown and described.

2. The arrangement of the lever M, weight N, staypiece 0, and crank-shaft P, as shown and described.

In testimony whereof, I have hereunto set my signature, this 14th day of October, A. D. 1868.

JOHN ASHGROFT.

Witnesses:

ARTHUR B. WILLIAMs, A. NEILL.

The lever M is serrated atmfor adjustment andre-v stay-piece, 0, which holds the weight, when adjusted,v

the valve or valvefmechanism otherwise than by un- 

